Friction-clutch device.



VI. E. HINDMAN.

FRIGTION CLUTCH DEVICE. APPLICATION FILED MAY 7, 1912 Patented Mar. 10,1914 2 SHEETB-SHBET l.

WITNESSES x3/H @fw u .A Mmmm/ I. E. HINDMAN.

PRIGTION CLUTCH DEVICEA APPLICATION F1LBDMAY7,1912.

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Y Y a w r Du 2 t m um r'rnn stra'rns y PATENT GFFICE ISAIAII E. HINDMAN,0F GRAFTON, PENNSYLVANIA, ASSIGNOR T0 THE DUFIE MANU- FACTURING COMPANY,OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

FRICTIONCLUTCH DEVICE.

Specification of Letters Patent.

Patented Mar. 10,191.4.

To all whom t may concern Be it known that I, ISAIAH E. HINDMAN, aresident of Grafton, in the county of Allegheny and State ofPennsylvania,v have inL vented a new and useful Improvement inFriction-Clutch Devices, 0f which the following is a full, clear, andexactdescription, reference being had to the accompanying drawings,forming part of this specification, in which- Figure 1 is a verticalsection showing a preferred form of my invention as applied to a. screwjack. Fig. 2 is a cross-section on the line II-II of Fig. 1.'v Fig-3 isa partial side elevation showing a controlling device. Fig. 'el is aperspective View of the controlling ring. Fig. 5 is a detail of one ofthe clutch rollers, and Fig. 6 is a vertical section on the line VI--VIof Fig. 2.

My invention relates to friction clutch devices especially applicable tohigh speed screw jacks wherein t-he anule of the screw is sharper thanthe angle of5 repose; so that if released the load would rapidly lowerthe jack. It has been `well-known that such types of jack were highlyefficient owing to the high efficiency of quick pitch screw threads; butmany diiculties have presented themselves in obtaining a propermechanical device for holding the load while raising, and yet allowinglowering when desired. My invention is designed to overcome thesedifficulties and provide a mechanical clutch device which will hold theload during lifting and allow it to be lowered as desired; and whichshall give safety, shall be comparatively simpleyhighly etlicient, andwill prevent sinking back when the raising is stopped. y

In carrying out my invention YI provide a controlling ring co-actingwith anti-friction elements which are biased toward clutching position.The act of rotation in raising is arranged to coact with the controllingring in such a way that the anti-friction devices will not retard oroppose this movement; but will immediately engage as a clutch andprevent backward movement as soon as the raising rotation is stopped.

In the drawings, 2 represents the base of the jack having an upwardlyprojecting cylinder 3 provided with a head 4 having a central nut 5. Thequick pitch screw stern 6 extends down through the nut and has rotaryengagement with the piston 7 which is provided with a by-pass 8extending through` 1t and controlled by an upwardly seating ball valve9.

Surrounding the cylinder 3 is the lifting4 shell 10 which may have afoot-lift 11 at o ne side thereof, and carries at its top the liftlngplate 12. Extendin through a bearing 13 in the side of the she l is anoperating stud shaft 14 having a squared outer end 15 and carryingwithin the shell a bevel gear 16 intermeshing with horizontal bevel ear17, which is keyed to the threaded sha t 6. Surrounding the stem of thebevel gear 17 is a steel friction ring and ball race 18, having anannular groove in its upper face to receive a `row of balls 19 which arealso recelved by a corresponding annular groove in the upper ballbearing plate 20j This ball bearing plate 2() 'is centered by a reducedeX- tension 21 on the elevating screw.

Outside the friction ring 18, I place the controller 22, preferably ofthe silent cam clutch type7 which is split at an odd number of points,as shown at 23, to receive rollers 24. These rollers are of greaterdiameter than the thickness of the ring and engage the friction ring 18within them and curved cam faces 25 outside them and formed on the innersurface of a cam rin 25 which is forced into theupper part of t e shellwith a press lit. There are, of course, as many cam surfaces 25 as thereare rollers or antifriction elements, ,24, and the cam faces are sopositioned relative to the screw thread of the elevating screw thatduring lifting the friction of rotation tends to carry'the anti-frictionelements into released position at the deepest part of the cam grooves.

In order to cause the rollers or anti-friction clutch devices to stopbackward movement and hold'the load 1n any position to which it israised, some kind of biasing device is necessary which will'constantlytend to move the parts into clutchin position. In the form shown, Iaccomplish t is by providing a stem or pin 26 which is secured to theupper enlarged diameter portion of the controller rin 22, and rejectsoutwardly through the s ell. On t is shell, I form a small casing 27,preferably by casting it integral with the casing, which contains aspring 28 surrounding the stem 29 of a bearin'g block 30 fitting theside of the pin 26.

` The spring has a constant tendency to turn -the controller ring in aclockwise direction,

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looking atFig. 2, and hence to force the rollers into clutchingposition. This 4will lnot cause the rollers to oppose the rotation inlifting, but will cause the rollers to con- 5 stantly follow lup thelifting movement and always be ready to engage and check any backwardmovement.

is found that no settling back can be discerned when the lifting isstopped. This i feature is of great importance, because such l jacks areusually operated with aratchet lift and if a certainvamount oflift islost at each stroke, this means a large reduction in eiiciency.

The controller ring and clutch device which I have just described may beused to advantage with any rapid action screw jack havin Y screw of sucha pitch that the load will ower itself and the jack unless backwardmovement is stopped. .E

In my jack in order to lower, it is only necessary to apply power to theshaft 14 in the reverse direction from that of lifting, which power willbreak the friction connection between -thebevel gear 17 andits'surrounding friction ring 18, thus allowing the rotation in theopposite direction and gradually lowering :1s-desired The parts are sodesigned that the friction between the bevel gear and its friction ringcan never be overcome by any load within the range of the jack, thusIpreventing any accidental dropping of the jack under the load. i

The parts above described, afford a complete screw jack since I therebyprovide for lifting, prevent` all backward movement when the lifting isstopped and have lowering under control. In order to further pro-v vide,however, for regulating the lowering of the load without turning` of theactuating gear, I have shown the jack as provided with-a fluid dash potdevice and'a knockoff device which completely releases clutch device andallows the load to descend by leakage of-the oil or other liquid in thedash pot. It will be understood, however,

that the parts which I will nowv describe need not be used with theinvention covered herein. In using these further features, I fill thecylinder `and* bore of the casing with oil up to about the level shownin Fig. l,

which oil must be forced around the piston and past its'packing rings inorder toallow descent of the shell.- This regulates the speed ofdescent. In order to'allow the load to thus force the shell downwardly,I provide a knock-oli device for the clutch or controller rin In theform shown this coacts with t e biasing device. It consists of avertically movable wedge 31 having a wedge face 32, a straight face 3 3,and an engagement slot 34:. This wedge slides with.-y

in suitable slots in the casing 27 and 'the shell is provided with asuitable fulcrum or rest 35 to receive alever indicated inl dotted Inactual practice, it

lines at 36, which" may be engagedl with the wedge.

When it is desired to allow the load to -move down under the fluid'control, the

wedge. is forced `upwardly into the position shown in full lines in Fig.3. This turns the'controller ring to a position where the rollers are atthe deepest parts of the cam v grooves and out of action and holds themin this position. In this case the friction ring will revolve as a partof the bevel wheel 17 and the load will push down the shell as rapidlyas the transfer. of the Huid from the lower to the upper side of thepiston will permit. In such form thefluidv will 30 pass freely fromabove the piston to below f' the piston during liftin since the ballvalvev in the piston head will rop in its seat.

It will be noted that the base is provided with a central hole filledwith a screw plug V,535 87 in the form shown, thus providing forl propermachining of the inner surface of the cylinder. Where oil is used, thisis preferably filled in through a hole 38 in the top i plate '12 whichisv closed with the screw .90 plug 39.

'Ihe advantages of my invention will be obvious to those` skilled in theart. Pro-- vision is made for the use of a rapid pitch screw jackwithout the settling back or sliding backward movement kof the load ateach stroke duri ng lifting. The clutching action is distributedsubstantially equidistant around the screw, thus' avoiding uneven wearand tendency to canting. The biasing device retains theclutchmembers inposition ready to engage the moment that `lifting is 4 stopped. At thesame time, 'the load may be lowered as desired by reversed power appliedto the actuating shaft. The device gives safety, and eioiency, and isnot liable to Aget out of order.l

It will be understood that vI/am not claiming in vthis application theknock-off and dash pot arrangement, as this is claimed in v my PatentNo. 1,054,413, dated Feb. 25,1913.

,The invention herein claimed may be used with or without suchadditional parts or other added features, as it maybe desired.

The form ofclutch may be varied, the means for biasing the same may bechanged, and other changes may be made without departing from myinvention. i

I claim:

1. The combinationwith a rotary mem- 12C ber, of a friction ringcoacting with the rotary member, a controller element around the ring,antifriction elements coacting with the controller element, an elementhaving a series of cam surfaces to coact with the anti- 12.5

,friction elements, and a biasing device, substantially as described.

` 2. The combination with a rotary member,- a friction ring, a earnclutch coacting therewith,jand a'spring-actuated biasing deviceA 13*ber, of a friction ring, a controller ring surrounding it, antifrictiondevices carried by the controller ring, a surrounding element having camgrooves coacting with the rollers, and a biasing device engaging thecontroller ring, substantially as described.

4. The `combination with a rotary member, of a friction ring coactingwith the said member, a controller element around the ring, antifrictionelements coacting with the controller element, an element having aseries of cam surfaces to coact with the anti? friction element, abiasing device, and a knock-off .for the biasing device, substantiallyas described.`

-5. In a device of the character described, the combination of a rotarymember having a gear attached thereto, a friction ring carried by thegear, an upper bearing plate, a series of balls between the upperbearing plate and friction ring, a controller element 'surrounding thefriction ring, and having vertical slots therein, rollers journaled insaid slots, and adapted to contact with the friction ring, and a camelement surrounding the controller and having cam surfaces also engagedby said rollers, substantially as described.1

6. In a device of the character described, the combination of a rotarymember having a gear attached thereto, a friction ring carbearing late,a series of balls between 4the upper bearing plate and friction ring, acontroller element surrounding the friction ring, and having verticalslots therein, rollers journaled in said slots and adapted to contactwith the friction ring, and a cam element surround- Vlng the controllerand having cam surfaces also engaged by said rollers, together with abiasing device connected to the controller ring, substantially asdescribed.

7. In a device of the character described, the combination of a rotarymember having a gear attached thereto, a friction ring carried by thegear, an upper bearing plate, a series of balls between the upperbearing plate and friction ring, a controller element surrounding'thefriction ring and having vertical slots therein, rollers journaled insaid slots and adapted to contact with the friction element, a camelement surrounding the controller and having cam surfaces also engagedby said rollers, together with a biasing device connected to thecontroller ring, and a knock-off device for the clutch or controllerring, substantially as described.

8. In a device of the character described,

the combination of a rotary member, a friction ring carried thereby, acontroller elei ment around the ring, antifriction clutch elemen'tscoacting with the controller elei ment, a cam member'surrounding thecontroller element and acting upon` the friction elements, a biasingdevice for normally holding the controller in 'one position, and a'knock-off device for. overcoming the action of the biasing device,substantially as described.,

9. A friction clutch device comprising a friction ring, a rotary memberto which the ring is attached, a controller element around the ring,anti-friction elements co-acting with the controller element, andanother element having a series ofcam surfaces to coact with theantifriction elements; substantially as described.,

In testimony whereof, I have hereunto set my hand.

ISAIAH E. HINDMAN.

Witnesses:

G'Eo. B. BLEMING, C. P. BYRNES.

